Amateur-built Beaver DHC-2 MK.1 accident near Kalispell, Montana, July 24, 2007
On July 24, 2007, a amateur-built Beaver DHC-2 MK.1, registered N6784L, was substantially damaged in an accident near Kalispell, Montana. It was a personal flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A loss of engine power due to the failure of the supercharger impeller bushing, which allowed raw oil to enter the induction system.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 24, 2007
- Place
- Kalispell, Montana
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built Beaver DHC-2 MK.1
- Registration
- N6784L · no longer on the register · serial 273
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While in cruise flight over a wilderness area, the engine sputtered and then lost power. The pilots attempted to restart the engine, and then began to look for a place to land. The pilot landed the airplane on a gravel/sand bar area near a river. The airplane sustained structural damage to the firewall, a wing strut, and leading edge damage to the horizontal stabilizer. The pilots reported that the oil pressure and cylinder head temperature gages were in the green prior to the event, and there was no indication that there was anything wrong. An inspection of the engine revealed that the master rod end had broken. No metal pieces were observed in either the oil filter or oil sump. Further inspection of the engine revealed that the supercharger impeller shaft bearings (blower bushing) had failed. The supercharger impeller bearings are an area that requires lubrication, and if they fail, raw oil can be pumped into the induction system, which could cause various engine problems, including detonation.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; single-engine sea; instructor: airplane single-engine; instrument: airplane
- Flight time: 2,167 hours in all; 350 in this make and model; 36 in the last 90 days; 25 in the last 30 days; 1,967 as pilot in command
- Last flight review: January 1, 2007
- Medical certificate: Class 2
- Seat: left
- Injury: no injuries
Dual student
- Certificate: student
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 13,600 hours
- Last inspection: annual inspection, July 1, 2006
- Maximum gross weight: 5,370 lb
- Seats: 7
- Landing gear: fixed
- Engine: Pratt & Whitney R-985 (piston); 0 hours total
The flight
- Departed from: BVS Mount Vernon WA at 9:00 pm
- Destination: LWT Lewiston MT
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 210° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 93°F (34°C), dew point 54°F (12°C)
- Altimeter: 29.78 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.